Single conductor locking connector



Sept. 12, 1950 H. HUBBELL ETAL SINGLE CONDUCTOR LOCKING CONNECTOR FiledFeb. 2, 1944 Q %V%//////// /////////////////m,/n 1% 7 7 x 2% i 9 Z IWfix 3 m Ev Patented Sept. 12, 1950 UNITED STATES PATENT OFFICE SINGLECONDUCTOR LOCKING CONNECTOR Application February 2, 1944, Serial No.520,996

12 Claims.

This invention relates to a connector for connecting electricalconductors or leads, and has for an object to provide a simple andeffective means for connecting such conductors which is of very simpleconstruction and may be easily and quickly manipulated to either connector disconnect the conductors, but in which, after the connection ismade, the conductors are substantially locked so that they will notseparate inadvertently or with considerable strain on the conductors,although it is preferred that the connection yield or separate beforethere is sufficient strain to break the lead or conductor.

Another object is to provide a connector which will insure goodelectrical contact without the necessity of soldering or similaroperations.

With the foregoing and other objects in View we have devised theconstruction illustrated in the accompanying drawing forming a part ofthis specification. It is, however, to be understood the device is notlimited to the specific construction and arrangement shown but mayinclude various changes and modifications within the scope of theinvention.

In these drawings:

Fig. 1 is a partial side elevation and partial longitudinal sectionthrough a connector with the conductors connected thereby;

Fig. 2 is a similar view showing a slight modification;

Fig. 3 is a side elevation of the connector of Fig. 2 with theconductors removed;

Fig. 4 is a view similar to Figs. 1 and 2 showing another modification;

Fig. 5 is a, similar view showing another modification more particularlyadapted for large connectors;

Fig. 6 is a transverse section substantially on line 66 of Fig. 4, and

Fig. 7 is a longitudinal section showing one way of securing the springagainst turning.

Referring first to Fig. 1, the connector comprises an external sleevell] enclosing a substantially cylindrical coiled spring I l, the ends ofthe sleeve It being turned inwardly, as indicated at l2, to retain thespring within the sleeve, and these inturned ends are provided withopenings for insertion of pins l3 connected in any suitable or desiredmanner to the insulated or other leads or conductors Hi. The internaldiameter of the coils of the spring I l is somewhat less than theexternal diameters of the pins I3 so that when the pins are inserted inthe spring the spring is. expanded somewhat and due. to its resilientaction firmly grips the pins, making good electrical contact therewithand also substantially locking the pins within the connector, becausewhen there is strain placed on the pins, tending to pull them straightout from the spring, this action tends to elongate the spring and thiselongatingaction tends to contract the coils of the spring making themgrip the pin more firmly. In fact the greater the tension tending topull out the pin the greater is the gripping action of the spring on thepin. The pin, however, may be readily inserted in or removed from thespring by applying a relative turning action between the spring and thepin while pushing the pin into the spring or drawing it out of thespring. Thus, when inserting the pin into the spring, if it is turned inthe direction opposite to the direction of the coiling of the spring itwill tend to unwind the spring making it somewhat larger or expanding its that the pin will readily move into the coil. Thus for example, if thespring is wound left-hand or counterclockwise, when inserting the pin ifit is turned to the right or clockwise at the same time the force isapplied tending to push the pin into the spring it will tend to open upor expand the spring and the pin will readily slide into place.Similarly, if it is desired to disconnect the conductor or remove thepin from the connector, if tension is applied tending to pull it out ofthe spring and at the same time it is'turned to the right or clockwiseit will expand the spring sufficiently to permit ready withdrawal of thepin from the spring. But, as indicated above, a straight pull on the pinwithout the relative turning action would tend to elongate the springand tend to grip the pin more tightly and efiectively preventinadvertent separation of the pin from the connector or release of thepin under severe strain.

However, as the surface of the pin is preferably substantiallycylindrical and relatively smooth, the pin and spring may be so designedor proportioned that there is not a positive complete looking of the pinin the spring but the maximum grip of the spring is such that the pinwill be withdrawn before there is sufficient strain to break the lead orthe connector. In the arrangement shown in Fig. 1, both pins are grippedand held by the operator for insertion or removal of one pin when theother pin is in place in the spring, but in the disconnecting operationonly one pin will be removed because there is always a slight variationin the different end portions of the spring and the pins so that one pinis always gripped somewhat tighter than the other, and the '65 lesstightly gripped pin will be the one that is released under the relativeturning and pulling operation. With this arrangement of Fig. 1 while onepin is removed the other pin remains within the connector. In otherwords, only one pin can be removed and the connector will remainattached to the other pin or conductor, because after one pin isremoved, if it is attempted to remove the other pin by gripping itandthe sleeve ID, the sleeve will merely turn on the spring and therewill be nothing to hold the spring to secure relative turning of the pinin the spring to give the expanding operation.

In Figs. 2 and 3 is shown a slight modification in which after one pinis removed from the connector the other pin may also .be removed. .Orthat is, with this construction either one or both pins may be removed.To secure this effect means is provided to permit limited turningmovement only of one end of the spring in the sleeve. In the arrangementshown, one end of the spring is turned outwardly, as indicated at i5,and seated in an elongated recess or slot H5 in the sleeve [0. This willpermit sufficient relative turning movement of the spring in the sleeveto secure the necessary expanding operation of the spring to release thepin, but it will also prevent turning of the-spring in the sleeve afterone pin has been removed so that the other pin may also be turnedrelative to the spring to expand the spring sufficiently to release thispin also.

To insure that there is sufiicient electrical conducting capacitythrough the connector it is preferred that the end walls l2 be pinchedinwardly far enough to tightly grip the outer surtaces of the pins 13 tomake good electrical contact so that the outer sleeve forms asupplementary conductor for the spring, and the portion of the springbetween the inner ends .of the pins is not required to carry the fullcurrent. For this purpose the openings in the .end walls l2 may besomewhat smaller in diameter than the exterior diameter of the pins andthe sleeve it be a longitudinally split sleeve, as indicated at 1, Fig.6, and made as a spring or resilient sleeve so that when the pins areinserted they will slightly expand the sleeve and its resilient aptionwill clamp the end walls against the pin to insure good electricalcontact. The conducting capacity of the spring may also be supplementedby an independent conducting sleeve l8. This may be a relatively thinbronze spring sleeve longitudinally split at one side, as indicated atI9, Fig. 6, and embracing the spring and by its re silient actiontending to clamp itself against the outer periphery of the spring togive a good electrical contact therewith. This sleeve is of sufficientlength so as to extend outwardly well beyond the free inner ends of thepins 13 and well overlap these pins so as to effectively supplement theconducting capacity of the portion of the spring between the inner freeends of the pins. Also as it is a split spring sleeve it will yield orexpand to permit the spring to expand for the inserting and removaloperations of the pins as described above.

In Fig. 4 is shown a slight modification in which the coil spring 23corresponding to the spring II is of flat wire instead of round wire, asshown in Figs. 1 and 2. The operation and effect is the same except thatthis gives greater conductive effect for the spring, that is, greatercross sectional area of the wire for a smaller external diameter,permitting the use of stronger springs with greater cross sectionsWithout materially increasing the diameter of the connector. Flat wirealso increases the gripping surface between the wire and the pin andelectrical contact. This spring may also have the outwardly turned end2| extending into an elongated slot or recess 22 in the sleeve ID forthe same effect as the outwardly turned end IS in the slot or recess l6of the first form, to permit limited relative turning movement betweenthe spring and the pin, and permit removal of either pin and preventcollapse of the spring. In either form if it is desired to have theconnector permanently connected to one conductor and have it adapted forinsertion and removal of a single pin, one end of the spring may bepermanently connected to one lead or conductor or to the sleeve ID bysoldering, brazing or other suitable means.

In Fig. 5 is shown a modified construction intended more particularlyfor use with relatively large conductors for relatively heavy current.In this case the enclosing member or sleeve 23 corresponding to theexternal sleeve in has a chamber 24 in which the coiled substantiallycylindrical spring 25 corresponding with the springs Ii and 26 may belocated. The chamber 24 is closed at one end and the member is providedwith a flattened portion 26 to which the lead or conductor 21 may beconnected by any suitable means such as the screw 28. The pin 29corresponding to the pins 13 is connected to a block also having aflattened portion 3| to which the other lead 32 may be similarlyconnected by a screw 33. The end of sleeve 23 opposite the end portion26 is turned inwardly as indicated at 34 corresponding to the ends ofthe sleeve H] in the other forms and may be arranged to grip or tightlycontact pin 29 to give good electrical connection, as described inconnection with the first form, this sleeve being also preferably asplit spring sleeve to secure this effect. Also the free end of thespring 25 may be turned outwardly as shown at 35 to extend into anelongated slot or recess 36 in the sleeve to permit limited turningmovements only between the spring and the sleeve to insure release ofthe pin from the spring and also to prevent collapse of the spring, asdescribed in connection with the other forms. The whole connector may beenclosed in an insulating cover 31 made of rubber or suitablecomposition and it is preferably composed of two sections 38 and 39, thesection 38 enclosing the sleeve 23 and its connecting means to theconductor 21, while the section 39 encloses the outer block or endportion 30 of the pin and the means for connecting it to the conductor32. There is preferably a telescoping joint 40 between the adjacent endsof sections 38 and 39 to make a closed joint. The inner end portion 4!of the spring could be free in the enclosed sleeve or it could beanchored to the sleeve as by soldering, brazing or other suitable means.

In Fig. '7 is shown another way in which the spring H may be held fromturning in the sleeve I!) so that both pins l3 may be disconnected. Inthis arrangement after the spring I I is assembled in the sleeve In,either with or without the sleeve l8, the side walls of the sleeve arepunched inwardly as indicated at 42, preferably from opposite sides ofthe sleeve and two or four of these punchings may be used. As the wallsof the sleeve are punched inwardly projections 43 are formed on theinner side of the sleeve, and if sleeve I8 is used similar projectionsare formed in this sleeve, which extend between coils of the spring andseparate them or may bend the wire of the spring, effectively holdingthe spring against turning in the sleeve. These punchings may be usedeither in conjunction with or independently of the out-turned ends I5,2| and 35 of the spring seated in openings in the enclosing sleeve. Thisis a quicker "way of securing the spring.

It will be understood from the above the device is of very simpleconstruction and that the pins connected to the leads or conductors maybe inserted in or removed from the connector easily and quickly by avery simple operation, but that when inserted in the connector the pinsare tightly clamped and substantially locked against inadvertentseparation or removal from the connector. Also that although theconnector may be made in practically any sizes, depending on the sizesof the conductors and the currentcarrying capacities required, still itsoverall size .is not much greater than the conductors with theirinsulation or the connecting portions of the pins connected to theconductors. In fact, the whole connector for numbers l6 and 18 wire isless than 21 inch in length and less than 4 inch in diameter.

Having thus set forth the nature of our invention, what we claim is:

v 1. A connector of the character described comprising a substantiallycylindrical coiled spring adapted for connection to a conductor andhaving an open free end portion adapted for insertion of a substantiallycylindrical pin connected to another conductor, the internal diameter ofsaid free end portion being somewhat less than the external diameter ofthe pin so that said spring will grip the pin after insertion therein,and a split spring sleeve surrounding the spring and provided with aninturned end to retain the spring in the sleeve, and said inturned endbeing provided with an opening of less diameter than the pin so that asthe pin is inserted it expands the sleeve to cause the inturned end togrip the pin to provide close electrical contact therewith.

2. A connector of the character described comprising a substantiallycylindrical coiled spring, a split spring sleeve enclosing the springincluding inturned ends to retain the spring in the sleeve and providedwith openings for insertion of substantially cylindrical pins into theopen ends of the spring, said openings being of less diameter than thepins so that as the pins are inserted the sleeve is expanded to causethe inturned ends to grip the pins to provide close electrical contacttherewith, and the internal diameter of the spring being somewhat lessthan the external diameter of the pins so that the spring will grip thepins after they are inserted therein.

3. A connector of the character described comprising a substantiallycylindrical coiled spring adapted for connection to a conductor andhaving an open free end portion adapted for insertion of a substantiallycylindrical pin connected to another conductor, the internal diameter ofthe spring being somewhat less than the external diameter of the pin sothat said spring will grip the pin after the pin is inserted therein,and a split resilient conducting sleeve embracing the spring and of aninternal diameter such that it is expanded by the spring as the pin isinserted and thus provides close electrical contact with the spring tosupplement the electrical conducting capacity of the spring.

4. A connector of the character described comprising a substantiallycylindrical coiled spring, a sleeve enclosing the spring includinginturned ends to retain the spring in the sleeve and provided withopenings for insertion of substantially cylindrical pins into the openends of the spring, the internal diameter of the spring being somewhatless than the external diameters of the pins so that the spring willgrip the pins after they are inserted therein, and a split resilientconducting sleeve embracing and contacting the spring and of sufficientlength tooverlap th free end portions of both pins when they areinserted. in the spring.

5. A connector of the character described comprising a substantiallycylindrical coiled spring adapted for connection to a conductor andhaving an open free end portion adapted for insertion of a substantiallycylindrical pin connected to another conductor, the internal diameter ofthe spring being somewhat less than the external diameter of the pin sothat said spring will grip the pin after the pin is inserted therein, anenclosing member provided with a chamber in which the spring is locatedand provided with an inwardly extending end wall to prevent withdrawalof the spring from the chamber, said end wall being provided with anopening for insertion of the pin into the spring, the free end of thespring being turned outwardly, and said enclosing member being providedwith an elongated recess to receive said outturned end and cooperatetherewith to limit turning movements of the spring in the chamber.

6. A connector of the character described comprising a substantiallycylindrical coiled spring, a sleeve enclosing the spring includinginturned ends to retain the spring in the sleeve and provided withopenings for insertion of substantially cylindrical pins into the openends of the spring, the internal diameter of the spring being somewhatless than the external diameters of the pins so that the spring willgrip the pins after they are inserted therein, one end of the springbeing turned outward,- and said sleeve being provided with an elongatedrecess to receive said outturned end to limit turning movements of thespring in the sleeve.

'7. A connector of the character described comprising a substantiallycylindrical coiled spring, a split spring sleeve enclosing the springincluding inturned ends to retain the spring in the sleeve and providedwith openings for insertion of substantially cylindrical pins into theopen ends of the spring, said openings being of somewhat less diameterthan the pins so as to expand the sleeve by insertion of the pins andthe inturned ends are clamped on the pins to provide close electricalcontact therewith, the internal diameter of the spring being somewhatless than the external diameters of the pins; so that the spring willgrip the pins after they are inserted therein, and cooperating means onone :free end portion of the spring and the sleeve to permit limitedturning movement only of the spring in the sleeve.

8. A connector of the character described comprising a substantiallycylindrical coiled spring, a split spring sleeve enclosing the springincluding inturned ends to retain the spring in the sleeve and providedwith openings for insertion of substantially cylindrical pins into theopen ends of the spring, said openings being of somewhat less diameterthan the pins so as to expand the sleeve by insertion of the pins andthe inturned ends are clamped on the pins to pro- I videclose'electrical contact therewith, the ';internal diameter of thespring vbeing somewhat less than the external diameters of :the upinssothat the spring will ,grip the pins' after theyare inserted therein, andmeans to limit turning movements of the spring in the-sleeve.

9. A connector of the character described'comprising a substantiallycylindrical coiled spring, a sleeve enclosing the spring includinginturned ends to retain the spring in the sleeve and provided withopenings for insertion of substantially cylindrical pins into the open,ends of the spring, the internal diameter of the spring being :somewhatless than the external diameters of the pins so that the spring willgrip'the'pins after-they are inserted therein, and inwardly projectinglugs on the sleeve engagingthe spring andlimiting turning movements ofthe springinthe sleeve.

10. A connector of the character described comprising a substantiallycylindrical coiled spring, a split springsleeve enclosingtherspringincluding an inturned end'to retaintthe :spring in the sleeve andprovided with an openingfor insertion of a substantially cylindrical pininto the open end of the spring, said opening-beinggof a size somewhatsmaller than the 'pin so that the sleeve is expanded by insertion of thepin to cause the inturned ends to grip thee-pin andiprovide closeelectrical contact therewith, andthe internal diameter of the springv:loeingsomewhat 4 less than the external diameter of the pin so thatthe spring will grip the pin after it is inserted therein.

11. A connector of the character described comprising a substantiallycylindrical coiled spring adapted for 00111160171011.1130 aconductor andhaving an .open free end-portion adapted for insertion of asubstantiallycylindrical'pin connected to another conductor,the-internal'diameter of the springwbeing somewhat-lessthan o theexternal diameter-10f th lpin so ,thatzsaid spring will grip the pinafter the, pin is inserted therein, a split resilient conductingssleeve.embracing the spring-providedwith aninwardly extending end wall toprevent withdrawal of the spring from the sleeve, and said end wallbeing provided with an opening for insertion of the pin into the springand of less diameter than the pin so that the sleeve will be expanded asthe pin is inserted to cause said end-wall to grip the pin and provideclose electrical contact therewith.

12. ,A connector of the character described comprising a substantiallycylindrical coiled spring adapted for connection to a conductor andhaving an open free end portion adapted for insertion of a substantiallycylindrical pin connected to another conductor, the internal diameter ofthe spring being somewhat less than the external diameter of the pin sothat said spring will grip the pin after the pin is inserted therein,and. a split resilient conducting sleeve embracing and closelycontacting the spring and of a length to overlap a portion of the pinand extend beyond the free end portion thereof when the pin is insertedin the spring to supplement the electrical conducting capacity of thespring.

HARVEY I-IUBBELL. JOSEPH F. l-lIEALY, JR.

REFERENCES CITED The following references are of record in'the file ofthis patent:

UNITED STATES PATENTS Number Name Date 839,260 Benson Dec. 25, 1906978,630 Oettgen Dec. 13, 1910 1,441,045 Tredwell Jan. 2, 1923 2,261,372Holke Nov. 4, 1941 2,427,001 Hubbell et a1. Sept. 9, 1947 FOREIGNPATENTS Number Country Date 47,858 Switzerland June 9, 1909 91,452Austria Feb. 26, 1923 105,795 Australia Nov. 24, 1938 828,535 France May19, 1938

